The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Propulsion systems in motor vehicles require lubrication and cooling using a hydraulic fluid or oil to continuously operate. More specifically, the engine and especially a transmission require lubricating and cooling fluids or oils to maintain their operation and extend their useful life. The fluid is communicated throughout the transmission via hydraulic passages. Transmissions use oil pans to collect and store fluid, or oil. This fluid, or oil is for a pump, such as for automatic, CVT, or other transmissions, and/or for splash lubrication, such as for manual, DCT, or other transmissions. The pans may be wet sump or dry sump, the former storing a larger volume of fluid than the latter.
A gear rotating in a fluid or oil medium (an example is the pan) will induce a fluid flow. This flow is arbitrary in nature and can collect on other rotating or non-rotating components. The thrown hydraulic fluid, being uncontrolled, causes splash from contact with other components, steady fluid, and/or different fluid flows. The fluid splashing back onto the rotating assembly can induce drag from the fluid impact. In addition, the fluid coming in contact with a rotating component can resist its motion causing additional drag and loss of power.
The loss associated with fluid resistance to flow is known as churning loss while that of thrown fluid is referred to as fluid impact loss. The consequence of too much fluid on rotation is more than mere friction. Fluid impacting on the rotating parts has a mass which must be accelerated during engine acceleration which therefore acts as a loss on efficiency.
In addition, splashing fluid leads to aeration of the fluid. High proportions of dissolved air in oil or hydraulic fluid can in turn lead to pump cavitation and excessive softness, for example in hydraulic-actuator force-versus-displacement characteristics. Dissolved air can also reduce the effectiveness of fluid lubrication and cooling properties. Accordingly, there is a need in the art for a device which allows recovery and control of at least a portion of fluid flow caused by a gear or rotating component in a fluid bath for a later use and/or to reduce fluid splash, drag losses and aeration.